System for feeding gases into a starting turbine



June 28, 1960 G. BAYARD 2,942,415

SYSTEM FOR FEEDING GASES INT0 A STARTING TURBINE Filed Nov. 25, 1955 G45 70N @A YARD powder'.

SYSTEM non FEEDING GASES INT A sTARrlNo TURBINE My invention has for its object a turbine-operatedjst'arting arrangement intended for speeding up rotary machmes and it covers more particularly, although not exclusively,

e an arrangement for starting turbine groups for which'it is necessary to ensure a speed of rotation at the start which is higher than that corresponding to the threshold of ignition while it is furthermore preferable for the starting unit to continuerotating with the turbine group during the rst part of its running period.

The arrangement described hereinbelow and incorporating my invention shows with reference to all similar `extant devices improvements which lead to substantial advantagesas to weight, bulk and operation by reason e. States f. f

` asians Patented j J une 28, 196,0

v produced by a bottle or a cooled compressor with a view to increasing the available energy of the air and chiey to avoiding any condensation of liquid inside the turbine or any carrying along of a liquid into the turbine. The amount of powder required is inconsiderable and the chief component of the operative mass of gases is constituted by air. This economical energy generator is, by reason of the presence of a supply of compressed air, comparatively heavy and bulky.

The pressures and the temperatures of the gases produced by the generator should be such that the racing speed of the starting unit fed by said gases, when idling, may be lower than the lowermost critical speed of the elements of said starting unit. This essential condition leads to reduced pressures and temperatures, the temperatures being vdelined also on the other hand by the requireof the technical structure designed for the starting arrangement and also of the supply of energy selected for feeding The actuallstarting unitconstituted by ay gas `turbine` driving the turbine group or the like'rotary` machine" pneumatically controlled clutch system;V according to a'prmary feature of my invention, such al starting unitv is exceedingly simple inits execution and in kits `opera' through the agencyof a suitablerrevducing' gear and a tion, its weight is reduced and its bulk is small; further more, it is possible, without modifying the starting unit in any. manner whatever both as concerns its execution and its adjustment, to feed it indiilierently through anylone of a Wide range of sources of energy f such for instance as gas-generators fed with slowburning powders, bottles of compresed air, air compressors, steam boilers. and the like.v p v A supply of energy adapted to produce a large amount of gases-several kilograms-within a comparatively short time, say about l0 seconds, under a pressure and at a temperature corresponding to theV conditions required for the feeding of the starting unit asA delined hereinafter. i Y i Y Y An automatic system for feeding the starting unit.

and the automatic systemvforfeeding the startingA unit form together what I may term a generator of energy;

Asfar as the invention is concerned, VI will now consider in the present specification a particular embodiment of such ,an energy generator, Ithe operation of which is simpleand speedy while it is highly adaptable, said embodiment `resorting to the thermal energyproduced by the combustion of a lt should be mentioned that the word powder as usedV in the present specification is intended to convey in the present casethe meaning of any simple or compound product reacting exothermically through ignition or admixture and appearing in a compact or condensed'shape,v

In the case of the construction of the generator, the

I thermal energy produced by lthe burning powderserves for heating a compressed gas, more particularly air, as

certain amount of a slow-burning ment that no condensation should be produced in the turbine, so that it is possible to resort for the casings and for the turbine to light alloys, which leads in its turn to a reduction in weight and to a greater ease of maching: it leads also to the deletion of the speed limiting device generally used for safety purposes, This speed limiting device may thus be eliminated without any drawback in the case where the energy generator operates only for a limited period; however, some type ofV speed-limiting device should be incorporated into the starting unit whenever the energy generator is to operate continuously or whenever the energy generator is to run for a period longer than the actual starting period, such a speed limiting device being designed so as to produce a stoppage of the starting unit, as soon as the turbine group has reached a sufcient speed. y

, The energy generator should also preferably be designed in a manner such that its operation may lead in a first stage to a feedingFof the starting unit under a reduced pressure, so as to'produce the engagement of the clutch.

in a gradual manner. i This second condition which eliminates any risk of an exaggerated'inertia torque due to the engagement of the clutchafter the turbine of the starting unit has been set running at a high speed, allows p exclusion of any torque limiting device and thus simpliiication of the star-ting unit. f It should be remarked that the torque produced by the turbine which is maximum at zero speed is limited bythe conditions under which the starting unit is fed.`

Further advantages of the arrangements -according to my invention will appear in the reading of the following description given, by way of exempliiication and by no means in a limiting sense, of my invention selected solely with a view to making my disclosure clearer.

The following description is limited to the general strui ture Yand tothe particular mechanical details of the starting arrangement. The details of execution which do not form part of my invention and which may be defined after a` simple'engineering'study are not disclosed with 'aview' to simplifying the description.

-In the accompanying drawing,- I have illustrated in Fig. l the above mentioned embodiment of my invention. In Fig. l, l yhave shown a particular example of the lconstruction adapted to use as a supply of energy a bottle 'T enclosing the clutch 8 adapted to control the transmission leading to'the'turbine group which is not illusf trated.

The starting turbineV 6- drives into rotation Vthrough the toothed wheelV 6 keyed toits shaft planet pinions 6 meshing with the stationary sunwheel 6"' so as to drive the planetrcarrier 6"" rigid with the driving section 10 of thev clutch'. Said section, fitted! on thenose ofy the output shaft of thespeed. reducing gear so as-toV revolve therewith, is adapted furthermore to Vexecute a` longitudinal translational movement.

Said clutch section 10- isrrigid with an annular piston 11 adapted to slide inside a chamber 12 connected with the pipe 5l feeding the starting unit through the branch pipe 13.

The distributor 4 connected with the starting turbine through the pipe-5 includes on the other hand:

An expansion chamber 14 communicating with the supply of compressed air 1-2-3 through a gauged port 15.

A powder-containing chamber 16 provided with a priming tube 17 adapted to ignite the cartridge bag 18.

An auxiliary chamber 19 communicating ,with the powder chamber through oneor more gauged ports 20.

A mixing or output chamber 21 into which communicates with the above mentioned pipe 5 and communicating,

furthermore on the one hand with the auxiliary chamber 19 through the ports 22 provided in the bottom of the movable piston 2 3 separating the two chambers 19 and 21 and on the other hand with the expansion chamber 14 through two valves 24 and 25, the large valve 25 being controlled by the said piston 23 andV being normally held in its closed position by a spring 26. Y

The head 27 of the smaller valve 24 is normally held in its open position by a pawl 28 controlled by the trigger' 29 controlled by the larger valve 2S. The spring Si?A urges the valve 24 back into its closed position as soon as the trigger 29 releases the pawl 28 as a consequence of the opening movement of the valve 25 engaging said trigger. A spring 31 returns the trigger'intoits original position when the valve 25 closes again and Vtheringshaped end 32 of the valve 24 allowsthe hand operation of last mentioned valve yfor resetting it after operation.

The gauged port or ports 20 serve-for maintaining insideV the powder-containing chamber a pressure suitable for a proper combustion of the powder.

The ports 22 serve for maintaining inside the intermediate chamber 19 the gases produced by the combustion of the powder under a pressure which is suicient for them to open the valve 25 and to hold it open during the combustion of the powder in the cartridge bag 18.

The gauged port -15 serves for limiting the throughput of the compressed air and consequently rthe pressure of the gases feeding the starting 'turbine when the valve 25 is open. Y

The small valve 24 serves yfor feeding-the starting turbine with a reduced throughput of air which'produces a low pressureduring the first stage of the startingperiod.,

Taking into account the preceding description andthe data relating to the operation of the different ports and members in the distributor, theV starting of the turbine group is performed as follows:

The coc-k 2 being opened, the compressed air flows and expands' through the port 15 and theopensmaller .valve 24 so as to produce van engagement of the clutch kelement- V 1d. whileV the Vstarting turbine starts rotatingy sponding to normal running conditions, since the,Y throughput of air isno longeriimited 'otherwise,thanV through the gauged portl'. The air passing through .the mixture chamber 21 is heated through admixture with high temperature gases entering said mixing chamber through the ports V22. During this stage, the turbine group is started running at a suitable speed and is ignited. When the powder in the cartridge bag 1S has been entirely burnt, vthe valve 25 is returned onto its seat by the spring 26. The feeding of the starting turbine is thus cut oif, the latter slows down and stops. At the moment at which the speed of the starting turybine drops below the speed of the turbine group, the clutch is disengaged. Y

The starting operation being at its end, the cock 2 is closed and the small valve 24 is reset through a transient drawingout of the ring-shaped end 32of the stem of said valve. The arrangement is thus ready to produce a further starting operation provided a suicient supply of compressed air is available for the purpose.

The cartridge bagy is designed in a manner such that itl produces a reduced pressure during the rst stage of the starting-period so that the engagement of the clutchy may be performed gradually and without any shocks.

This canbe obtained in any conventional manner through The preceding description has been given by way ofV a mere exempliication and by no means in a binding sense both as concerns the nature of the material to be usedv and the execution of the arrangement and as con-r cerns the number, shape, size, proportions and relative positioning of its different component parts or elements.

In fact, I-,may resort to any material and to any means and method for building my improved starting arrangement even if such material, means or method have not been speciiically mentioned hereinabove, without widening-thereby the scope of the invention as detined in the accompanying claims.

What I claim is:

' 1. In combination with a rotary machine, a starting arrangement comprising a starting turbine, a speed reducing gear controlled by said starting turbine, a clutch operatively inserted between the speed reducing gear and the rotary machine, a supply of compressed gas, a powder charge Ifor igniting same to produce combustion gases, two valves of dierent sizes mounted in parallel at the output of said supply of compressed gas, means for manually setting the smaller valve in its Open position, means wherethrough the combustion gases open the larger valve and close the ismaller valve, means returning automatically the larger valve into its closing position as soon as the combustion of the powder is at an end for admixing the combustion gases with the cornpressed gas to form a compound hot gasiform mixture and feeding said mixture simultaneously to the starting turbine to make the latter rotate and to the clutch to set the latter in its operative condition.

2. A system for feeding gases into a starting turbine, comprising a supply of a gasiform fluid under pressure, a combustion chamber containing a powder charge,` means for igniting said charge to produce combustion gases an intermediate chamber to the front of thecornbustion chamber,V communicating with the latter, a pistonshaped member slidably carried therein vand provided with at least one calibrated opening in its bottom to allow 'uidunder pressure, a valve controlled by said` piston Ythereby the mixing of the combustion gases produced with the uid under pressure to form therewith a compound hot gasiform mixture, and means connecting the` mixing chamber with the starting turbine to feed the latter with said mixture.

3. A system for feeding gases into a starting turbine, comprising a supply of a gasiform fluid under pressure, a combustion chamber containing a powder charge, means for igniting said charge to produce combustion gases, a mixing chamber, two halves of different sizes mounted in parallel at the output end of said supply, means for manually shifting4 the smaller valve into its open position, means wherethrough the combustion gases open the larger valve and'cloe th esmaller valve, means returning automatically the larger valve into its closing position as soon as the combustion of the powder is at an end, a mixing chamber fed with the fluid under pressure through the valve and with the combustion gases from the combustion chamber to form a mixture to be -fed to the starting turbine to make the latter rotate.

4. A system for feeding gases into a starting turbine,

comprising a container of a supply of gasi-form fluid under pressure, said container being provided with two output ports, a combustion chamber containing a'powder charge and provided with an output, means for igniting said charge to produce combustion gases, a mixingchamber including in its wall spaced inputs for the combustion gases passing through the output of the combustion chamber and for the gases produced by the supply and passing through the ports in the container, means for uncovering the -first Vport of the container prior to the ignition of the powder charge, auxiliary meansthrough which the combustion gases allow the gases to owout of the second port of the supply container into the mixing chamber through the second input to mix withthe combustion gases and to form therewith'a compound hot gasiform mixture, and means connecting the mixing chamber with the starting turbine to yfeed the latter with said mix- Y ture.

5. A system for feeding gases intoa starting turbine, comprising a container of a supply of gasiform uid charge and provided with an output, means for igniting 6 said charge to producercombustion gases, a mixing charnber including in its wall spaced inputs for the combustion gases passing through the output of the combustion chamber and for the gases produced by the supply and passing through the ports in the container, means for uncovering the first port of the container prior to the ignition of the powder charge, auxiliary mechanical means through which the combustion gases open the second input to.

allow the gases to iiow out of the second port of the supply container into the mixing chamber through the said second input to mix with the combustion gases and to form therewith a compound hot gasiform mixture, and means connecting the mixing chamber with the starting turbine to feed the latter with said mixture.

6. A system for feeding gases into a starting turbine, comprising a container of a supply of gasiform uid under pressure, a combustion chamber containing a powder charge, means for igniting said charge to produce combustion gases, a mixing chamber including in its wall spaced inputs for the combustion gases from the combustion chamber and for the gases produced by the supply, manually-operated means 4for delivering a iirst batch of *saidk uid pres-sure from the supply into the mixing chamber prior to ignition, auxiliary mechanical means through which'the combustion gases open the second input to -allow the gases to llow out of the supply container into the mixing chamber through said second input to mix with the combustion gases and to form therewith a compound hot gasiform mixture, and means connecting the mixing chamber with the starting turbine to .feed the latter with said mixture.

References Cited in the le of this patent UNITED STATES PATENTS Re. 13,217 De Ferrant Mar. 14, 1911 2,506,663 De Guerin May 9, 1950 2,620,627 Nardone k Dec. 9, 1952 2,737,938 Greenwald Mar. 13, 1956 2,754,657 Ehorn July 17, 1956 Y FOREIGN PATENTS Y 849,043 Germany Sept. 1-1, 1952 468,685 Great Britain .-.L.----...... Apr. 16, 1945 

